Unlike most of what happens at the Federal Communications Commission (FCC) in Washington, D.C., the raging debate over network neutrality has attracted the attention of businesses and activists nationwide — and now mayors, too.

This is for good reason: this fight implicates our most basic understanding of how the Internet works.

Net neutrality is a simple principle: that Internet service providers (ISPs) should treat all traffic equally, regardless of content or type of application. But the companies with monopolies on the lines that bring Internet into our homes — Comcast, Verizon, and AT&T — are doing everything in their power to put an end to that idea. They want to charge more, turning the Internet into a pay-to-play system favoring incumbents and those rich enough to compete.

This is antithetical the most basic notion of the Internet as a network that allows any and all equal access to speak. The Internet supports social hubs for marginalized and ostracized groups, provides a framework for political movements (both popular and unpopular), and acts a platform for startup businesses to thrive.

Many of today’s technology-enabled companies are challenging and changing entrenched business models, ideas, and institutions across all industries. These businesses drive our economic prosperity, create jobs, and improve our lives. And it is these companies that rely on strong net neutrality.

That’s why a seemingly arcane legal debate matters to those of us outside of the Beltway.

And it’s also why San Francisco Mayor Ed Lee is championing a strong resolution in favor of Net Neutrality at this week’s U.S. Conference of Mayors. Together with the mayors of Los Angeles, Seattle, and Tucson, Mayor Lee sent a letter to more than 1,300 mayors urging them to support his resolution. The mayors stated the obvious:

The Internet has thrived because of its openness and equality of access. Its level playing field is its core principle. The open Internet gives anyone with a big idea a real chance to compete. According to a survey by Consumer Reports, 71% of Americans would actively seek out an Internet service provider that followed Net Neutrality principles. The American people get it – Internet equality is critical to our nation’s prosperity.

Now the country has a few short months to submit comments on that proposal. In just the last 30 days, more than 128,000 citizens have heeded that call — a striking number to engage in an FCC rulemaking.

Mayor Lee, and those who have submitted comments, understand that the fight over net neutrality is not just about who gets faster access to a movie online, or who wins in a D.C.-lobbying battle. It’s about our cities and our local economies, and the right of citizens to communicate.

For now, the Internet still represents the promise of technology to fundamentally change the way we create and share. And this promise must exist equally, to everyone. If we get net neutrality wrong, we risk losing the Internet as we know it.

We applaud Mayor Lee and his colleagues for recognizing what’s at stake. We hope the FCC does the same.

Julie Samuels is the executive director of Engine, a research foundation and advocacy organization for tech entrepreneurs. Previously she was a Senior Staff Attorney and the Mark Cuban Chair to Eliminate Stupid Patents at EFF. Before becoming a lawyer, Julie was an assistant editor at the National Journal Group in D.C.